Vulnerability · Published Aug 18, 2026 · Assigned by VulnCheck
CVE-2026-74902SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload
High 8.6
In plain English
A high-severity cross-site scripting in siyuan from siyuan-note. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).
Severity (CVSS 3.1)8.6High
Exploit odds (30 days)0.2%top 90.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file upload validation flow that fails to escape filenames before inserting them into HTML via insertAdjacentHTML. Attackers can craft a malicious filename containing script payloads that execute with full OS command access when a user drags, drops, or pastes the file into the editor.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| siyuan-note | siyuan | 0 – before 3.7.4 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
References
- GitHub Security Advisory (GHSA-jf56-jrhq-j2qp) vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 XSS-to-RCE via malicious filename upload third-party-advisory